An adjusting device of this kind is disclosed in U.S. Pat. No. 6,254,046. Here, an adjusting device is described for connecting to a stand for a surgical microscope. With the adjusting device, a surgical microscope, which is accommodated on the stand, can be moved in a horizontal plane. This adjusting device has a base unit which is connected to a carrier arm of the stand. A housing is connected to this base unit wherein a slide disc is journalled and this slide disc functions as a load take-up unit. The slide disc holds a surgical microscope, which is accommodated on the stand, and this slide disc can be moved in a horizontal plane by means of two spindle drives.
U.S. Pat. No. 4,714,328 discloses a surgical microscope having an adjusting device which makes possible a movement of the surgical microscope, which is accommodated on the stand, in a horizontal direction. The adjusting device has a base unit which is carried by a stand arm and is coupled to a load take-up unit via a cross-slide guide. This load take-up unit carries the surgical microscope. Spindle drives are provided for driving the cross-slide guide.
European patent publication 1,222,986 discloses a machine tool which includes a machine table which can be shifted along two axes of movement orthogonal to each other. A toothed rack is provided as a longitudinal drive for the movement of this machine table in a horizontal plane. The toothed rack mechanism is combined with a spindle mechanism functioning as a transverse drive.